US2362946A - Spray gun - Google Patents

Description

Nov. 14, 1944. H. c. sTocKDALE SPRAY GUN Filed July 31, 1940 WSA/WP: www a fam/04a '/VEI/ h SN J Il, amg. mi.:

l tively high pressure.

Patented Nov. 1 4, 1944 SPRAY GUN Harry C. Stockdale,A Ravenna, Ohio, assignor to Food Machinery Corporation, San -lore, Cal a corporation of Delaware Application July 31, 1940,y Serial `N0. 348,749

1 Claim.

This invention relates to spray guns and particularly to spray guns operating' under rela- `It is an object of this invention to provide a novel and eiiicient spray gun, the operation of which is relatively easy and which embodies K means forcontrolling the form of the spray produced thereby which can be manipulated without removing the hands from the gun.

It is also an object of this invention to provide a, spray gun having a liquid guiding and controlling device for controlling the formation of a spray which may be readily removed as a unit from the barrel of the gun for the purpose of cleaning the same or replacing worn parts.

The manner of accomplishing'the aforesaid objects, 'as well as further objects and advantages, will be made manifest in the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional view through a preferred embodiment of the spray gun of my invention, showing the trigger valve closed and the spray control in a fine spray position.

Fig. 2 is a fragmentary view corresponding to the right hand half of Fig. l but illustrating the spray control mechanism positioned so' as to throw a solid pencil-like stream of liquid from said gun.

Fig. 3 is a view similar to Fig. lof the handle portion of said gun, illustrating the operation of the trigger mechanism to crack the valve open.

Fig. 4 is a view similar to Fig. 3 illustrating further opening of the trigger valve after this has been cracked, as shown in Fig. 3.

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 1 showing the liquid straightening spider provided in the invention.

Fig. 6 is a cross-sectional view taken on the line 6--6 of Fig. 1 and a front elevational view of the whirl member of said spray gun.

i member Il is a liquid passage I3, there being a hose connection I4 at the outer end of this for connecting a hose to the gun. Also provided in the butt member Il to control the passage I3 is a valve I5 including a valve ball I6 which is urged against a seat I1 by a pressure spring I8 and is adapted to be lifted from this se'a-t by a valve stem I9 which enters the passage I3 through a packing gland 20.

The pistol grip l2 is hollow and has fulcrum pins 25 and 26, which are disposed varying distance yfrom the stem I9, and a latch pin 21 on the opposite side of the stem therefrom. Mounted in the grip I2 is a trigger 30 having slots 3| and 32 which receive the pins 25 and 26 respectively as clearly shown inrFigs. 1 3, and 4.

Pivotally mounted by a pin 33 on the trigger 30 is a latch 34 having a hook 35 which is adapted to be hooked over the pin 21- when the trigger 30 is compressed so as to hold the valve I5 open. The position of the latch 34 when thus latching the trigger open is shown in broken lines in Fig. 4. The latch 34 is urged into the position in which it is shown in full lines in Figs. 1, 3, and 4 by a coil spring 36. Thus, if the trigger 30 is com? pressed to open the valve I5 and while it is compressed the latch 34 is rocked into the broken line' position 38 shown in Fig. 4 and the trigger released, the latch will hold the trigger in comp ressed position. In order to release the trigger 30 from the latch 34, it is now only necessary to press the trigger slightly, whereupon the spring 36 returns the latch to its full line position in the drawing so that when the hand is again relaxed from the' trigger, the latter returns4 to its full line position shown in Fig. 1.

It is also to be noted that in operating the valve I5 by the trigger 30, the initial motion of the latter, which cracks the valve-that is, which rst opens it against the pressure of liquid thereagainst--constitutes a rotation of the trigger 30 about the pin 26,- thus giving a high degree `of leverage to the trigger in cracking ther valve. After. the valve is cracked, however, not so much pressureis necessary to further open it, and in order to get a considerable movement during subsequent swinging of the trigger 30, the

pinv 25 provides afulcrum for the trigger 3|) as soon as the lost motion provided by the slot 3| is taken up. This situation is rst reached when the trigger is positioned as shown in Fig. 3, after which further inward swinging of the trigger 30 gives a disproportionately large movement of the ball I6 of the valve I5 as shown in Fig. 4.

The spray gun I0 also includes a primary barrel 40 and a secondary barrel 4I, adjacent ends of' which are connected in offset relation by an adapter 42. These barrels comprise cylindrical tubes which are relatively long when compared with the inside diameter thereof.

The primary barrel 40 is secured to the butt member II so as to communicate with the iiuid sleeve 45 rotatably mounted on the barrel 45 between the ring 44 and the butt member The sleeve 45 includes a cylindrical quill 45, the space inside which is partially relieved by a shallow recess 41 formed in the barrel 40. 'I'he quill 45 has a friction grip covering 45 which may be -of corrugated rubber and a cylindrical cam 49 'in which a cam groove 50 is formed.

'I'he secondary barrel 4| has a nozzle member 60 screwed into its front end, this nozzle member being of relatively small cross-section, the portion thereof of largest diameter being flush with the outer surface of the barrel 4I. The nozzle member 60 has a liquid whirling chamber .5I which is of smallerv diameter than the interior of the barrel 4| and is connected with this barrel'by a beveled fillet 52 provided on the inner end of the nozzle member 50. The chamber 5| has a tapered forward end which communicates with a narrow opening 53. The nozzle member 60 is formed with a nipple 54 which is threaded to receive a cap 55 which compresses a. disc 55 and a packing washer 61 against the front end of the nozzle, the disc 55 having a central aperture of a size suitable for particular kinds of spraying operations for which it is desired to usetheglm I0.

The adapter 42 is provided with an opening having a packing gland 59 which is concentric with the secondary barrel 4 I. Y

Longtudinally slidable in the secondary barrel 4| and self-guided by the interior surface of said barrel so as to be axially centered therein at all times under various operating conditions, is a liquid guiding and controlling device 10. This control device includes an assembly and operat.. ing shaft 1| which extends slidably through the gland 69 as shown in Figs. 1 and 2. The front end of this shaft is threaded into a liquid spreading and whirling head 12 having an expanding frusto-conical outer surface 13 and a counterfrusto-conical surface 14 at its front end, from which extends a tubular whirl sleeve 15. This sleeve has formed therein a series` of slots 15, the latter lying in planes which are parallel with the axis of the barrel 4| and equi-distant from said axis so that said slots 16 have a spiral relation to the axis of the barrel.

. It is to be noted that the sleeve 15 is of such a diameter as to slidably fit into the chamber 6| when the device 15 is slid in a rightward direc' tion in the barrel 4|. It is also to be noted that the frusto-conical surface 14 is disposed substantially parallel to the frusta-conical surface of the fillet 62 so that as the head 12 is moved to insert the sleeve 15 into the chamber 6| the annular passageway bounded by the frusto-conical surface 14 and the iillet 62 is uniform in thickness at various points therein.

The liquid guide and control device includes a spider sleeve 80 having a series of guide fins 8| preferably formed integrally therewith and extending outwardly to slic'iably engage with the inner surface of the secondary barrel 4i. 'I'he spider 80 is rigidly fixed upon the shaft 1| as by a pin 82. Snugly pressed over the shaft 1I is a stop sleeve 85 for limiting the rearward movement of the device 10.

Mounted on the rearwardly extending end of the shaft 1| is a cam follower nut 55 having a lug 81 which extends into the cam groove 55 of the cylindrical cam 49.

aseae Operation The gun I9 of this invention is adapted to be used for directing high pressure sprays with variable amounts of liquidand to deliver at option a rod-like stream of.` liquid. While applicable in many arts, this invention is particularly useful in the cleaning of automobiles.

Control of the amount of liquid contained in the spray or rod-like stream projected from .the gun is accomplished by the size of orifice in the disc 55. Turning the iiow onor of! is effected by the trigger 50. Control of the spread of the spray or the selective formation of a rod-.like stream of liquid is accomplished by 'rotation of the cylindrical control sleeve 45. Thisrotation operates through the cylindrical cam 49 to push and pull aon the rod 1| and thus slide the entire liquid guiding and controlling device 10 axially in the secondary barrel 4 I As already pointed out, the flns 8| of the spider sleeve 90 of the device 10 bear againstthe inner surface of the barrel 4| and maintain this device during said sliding movement at all times axially aligned with said barrel. This, of course, also y maintains the head 12 and sleeve 15 in true axial alignment with the nozzle member 50 and the whirling chamber 6| of the latter.

When the valve I5 is opened, by pressing on the trigger 35, the liquid rushes from the passage I5 through the barrel 40 and the adapter 42 into the barrel 4|. In passing through the latter barrel, the liquid is guided by the guide fins @l causing this liquid to travel in paths disposed `lust inside of the barrel 4| and parallel with the axis thereof. .After traveling through the spaces batween the fins 8|, the liquid enters the annular space surrounding the head 12 where it passes through an increasingly restricted annular passageway 90, from which it flows as a tubular sheet of liquid into an annular space 9| which`is disposed between the truste-conical face 14 and the reverse frusto-conical face of the fillet 52.

If the space 9| is opened up by the extreme rearward positioning of the device 10 as shown in Fig. 2, the liquid passes directly through the space 9| and the nozzle chamber 5|' and out through the central aperture in the nozzle disc 66 as a rod-like stream. The stream is thus formed with a high degree of efliciency, this being due to the axial direction imparted to the liquid as it travels between the guide fins 5| and the distention of these streams into a single tubelike sheet of liquid by the passage of these petween the head 12 and the barrel 4I. This tubelike stream of liquid is caused to converge when it strikes the fillet 62, and enters the chamber 6| with a minimum of friction and turbulence and thus produces a maximum of pressure and dynamic energy in the water occupying this chamber. This in turn produces a relatively high velocity in the rod-like stream of liquid expelled through the aperture in the disc 65.

In order to change this rod to a spray, the operator rotates the sleeve 45, thus propelling the guide and' control device 10 axially forwardly in the barrel 4|. Fig. 1 shows this operation carried to the point where a relatively fine spray will be emitted from the nozzle of the gun.

As the front end of the tubularwhirl sleeve 15 enters the cylindrical nozzle chamber 5|, the liquid which theretofore haspassed directly from the annular space 9| into the chamber 5|, is now forced to flow through the tangential slots 15 into the interior` of the sleeve 15 and thence into the chamber 6I. As the liquid enters this chamber after passing through the slots 18, itis whirling rapidly about the axis of the nozzle 60 and forms itself into a whirling spray as it passes outwardly through the aperture in the disc 66.

It is to be noted that the slots 16 are formed in planes which are parallel with the axis of the liquid guiding and controlling device 10 and are spaced uniformly from this axis, these slots being substantially the full length of the sleeve 15 and being uniformly pitched relative to the axis of the head 12.

Attention is called to the fact that as the head 12 of the device 10 is moved toward the nozzle member 60, after the sleeve 15 has once entered the chamber 6I, the eilectivel area of the slots 16 is gradually decreased, yet at the same time the angle of the effective portions of these slots relative to the axis of the head 12 remains the same. Thus, although diierent quantities of liquid are admitted to the chamber 6I for the formation of the whirling spray by the'gun I0, a relatively constant whirling tendency is imparted to thisv liquid as it enters this chamber, so that the spray formed by the gun I0, no matter what its intensity, is of substantially the same whirling character.

One of the important advantages of the present invention resides in the unitary character of the liquid guide and control device 10 which permits this to be assembled with and removed from the secondary lbarrel II of the spray gun as a unit for purposes of cleaning the same or replacing parts which may have become worn. In some instances, also, it is desirable to place the head 12 in use at a given time with another similar head having slots 15 which are differently pitched or of a different size. This may become necessary where the character of liquid to be handled by the gun I0 varies in density or viscosity, or where varying amounts of solid material may be entrained in the liquid handled by the gun.

In the present gun construction, it is to be noted that all of the operating parts of the gun may be exposed to view for the cleaning of the same by the simple operation of unscrewing the secondary barrel 4I from the adapter I2 and sliding this barrel oi of the guide and control device 10. In order to render this disassembly and re-assembly of the gun easy, a hex shoulder 95 is provided on the barrel II, which shoulder abuts against the adapter 42 when the barrel 4I is screwed into the latter.

Another advantage of the spray gun oi' my in. vention is the ease with which it may be handled and controlled by the operator. This gun is designedto be carried in the two hands, the pistol grip I2 being gripped in the right hand and the sleeve 45 being gripped in theA left hand. The hose is attached to the connection I4 which it is to be noted is above the pistol grip I2 so that when the hose is being pulled along by the oper-V ator of the gun it will tend to lift the gun instead of depress this.

In the commercial uses for which the spray gun of my invention is designed it is necessary to be able to quickly alter from time to time the character of the spray issuing from the nozzle of the gun. It is-also necessary at frequent intervals to shut the gun off completely and then recommence operations after a short pause. More often than not, it is desirable, when thus recommencing operations, to produce a spray of the same character as was being .produced before the gun was shut oif. The spray gun I0 of my invention may be operated in this manner without removing the hands from the gun, the function of turning on or shutting off the gun completely being effected by clinching the pistol grip I2 in the right handso as to swing the trigger 30 inwardly thus opening the valve I5, or the releasing of this grip so as to allow the spring I8 to close this valve and swing the trigger forwardly. The adjustment of the spray control device 10 is eiected by rotating the left hand in which the sleeve45 is gripped.

The design of my spray gun is thus seen to be such that it can be handled so as to direct the spray wherever desired and controlled so as to determine the character of the spray and turn on or shut off the gun without removing the hands from the grips or shifting these in any way from the positions in which the hands grip the gun.

I claim:

In a spray gun, the combination of: a primary tubular barrel; a secondary tubular barrel, the axis of which is offset from said primary barrel; adapter means connecting adjacent ends of said barrels; nozzle means provided in the free end of said secondary barrel; nozzle control means provided in said secondary barrel, said means including a rod for operating said control means;

a stuillng box in said adapter means through which said rod passes; a rotary grip provided on said primary barrel, there being a helical thread provided on said grip; and means on the extending end of said rod for engaging with said thread to permit said rod to be shifted axially by the rotation of said sleeve for the purpose of actuating said nozzle control means.

U HARRY C. STOCKDALE.

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